1. Field of the Invention
This invention relates generally to apparatus for shaking fruit and nut trees, and more particularly, but not by way of limitation, to tree shaking apparatus constructed for use with a conventional tractor power-take-off.
2. Description of the Prior Art
Two prior art devices for shaking trees, which devices have some similarities to the present invention are disclosed in U.S. Pat. Nos. 3,812,662 and 3,594,999, both to Savage.
Each of these prior art references disclose two eccentric weights rotating in substantially vertical planes to produce a vibrating force. The weights of each apparatus are not, however, constructed to rotate in substantially the same plane, but rather they rotate in spaced parallel planes. A disadvantage of having the two eccentric weights rotating in spaced planes is that the offset between the rotating weights creates a bending moment in their common shaft which causes undesirable loadings.
U.S. Pat. No. 3,812,662 shows a clamp means somewhat similar to that of the present invention. The clamp means of U.S. Pat. No. 3,812,622, however, has the hydraulic ram for extending the clamp means located within a tubular beam of the movable portion of the clamp means, whereas the present invention has such hydraulic ram offset from the sliding tubular beam.
It is seen, therefore, that although the prior art discloses apparatus for shaking trees having several of the features of the present invention, the present invention includes several distinct improvements providing important advantages over these prior art devices.